1. Field of the Invention
The present invention relates to abrasive articles and, more particularly, to an abrasive pad comprising a plurality of overlapping abrasive strips. Also disclosed is a related method of making such an abrasive pad.
2. Description of the Prior Art
Abrasive pads are generally well known in the art and are typically driven in rotation by the output shaft of a rotary or orbital tool to abrade material from a workpiece. One common type of abrasive pad, often called a square or cross pad, includes a pair of abrasive members disposed in a perpendicular relationship to each other. Each abrasive member in such a square or cross pad comprises at least one strip of coated abrasive cloth formed into a loop. A connector is disposed centrally within the abrasive pad and is attachable to a driven rotating shaft. Such abrasive pads are readily available on the market, for example, from Arc Abrasives Inc. of Troy, Ohio.
The above described abrasive pads are often used to abrade surfaces within tight corners or proximate joints of workpieces, and are widely used to abrade welds positioned in the corners of steel tanks. Such traditional square or cross pads suffer from the disadvantage of having sharp corners that often impact the surface being abraded when rotated. Such contact with the corners of the abrasive pad often makes the rotary or orbital supporting tool difficult to operate and reduces the efficiency of the abrading operation. Additionally, such impact typically accelerates wear and reduces the life expectancy of the abrasive pad. Contact between the corners and the workpiece also may cause discomfort or even repetitive stress injuries to a user.
A further disadvantage with traditional cross pads is that they provide a relatively limited abrasive edge surface for abrading a workpiece. As may be appreciated, the operator must therefore devote more time to remove material from the workpiece.
Accordingly, there remains a need for an abrasive pad having an extended abrasive edge surface and that also eliminates sharp corners from impacting the surface of the workpiece to be abraded.
Therefore, it is an object of the present invention to provide an abrasive pad of simple and inexpensive design.
It is another object of the invention to provide an abrasive pad that may be easily and removably mounted on a powered rotary member to rotate against a workpiece and provide an abrading action against the workpiece.
It is yet another object of the present invention to provide an abrasive pad having a long life.
It is a farther object of the invention to provide an abrasive pad that is disposable when the individual abrasive strips become worn.
It is still another object of the invention to provide an abrasive pad having no sharp corners and that may be readily used in tight corners and other confined areas.
It is another object of the present invention to provide an abrasive pad that prevents or reduces operator discomfort and injury.
It is yet another object of the present invention to provide an abrasive pad having an extended abrasive edge surface and that also eliminates sharp corners from impacting the surface of the workpiece to be abraded.
It is a further object of the present invention to provide a method of manufacturing such an abrasive pad that is simple and efficient.
These and other objects of the present invention will be apparent from the description that follows, the appended claims, and the drawings.
The present invention provides an abrasive pad that is removably attachable to a driven rotatable shaft for abrading a workpiece and a method of making such an abrasive pad. A preferred embodiment of the abrasive pad includes first, second, third, and fourth abrasive members each including an outwardly facing surface with a plurality of abrasive particles supported thereon. The first abrasive member is secured substantially perpendicular to the second abrasive member. The third abrasive member is positioned angularly intermediate the first and second abrasive members and secured to the second abrasive member. The fourth abrasive member is positioned substantially perpendicular to the third abrasive member and angularly intermediate the first and second abrasive members and is secured to the third abrasive member. Each of the abrasive members may be offset angularly from radially adjacent abrasive members by approximately 45xc2x0. Each of the abrasive members also may comprise a plurality of abrasive strips aligned in an overlapping relationship.
In another preferred embodiment, the abrasive pad includes a first abrasive member including an outwardly facing surface with a plurality of abrasive particles supported thereon and a second abrasive member defining a loop including an outwardly facing surface with a plurality of abrasive particles supported thereon. The first abrasive member is positioned substantially perpendicular to the second abrasive member and a central portion of the first abrasive member is received within the loop of the second abrasive member. A third abrasive member defining a loop including an outwardly facing surface with a plurality of abrasive particles supported thereon is positioned angularly intermediate the first and second abrasive members and a central portion of the second abrasive member is received within the loop of the third abrasive member. A fourth abrasive member defining a loop including an outwardly facing surface with a plurality of abrasive particles supported thereon is positioned substantially perpendicular to the third abrasive member and angularly intermediate the first and second abrasive members and a central portion of the third abrasive member is received within the loop of the fourth abrasive member. Each of the abrasive members may be offset angularly from radially adjacent abrasive members by approximately 45xc2x0. Each of the abrasive members also may comprise a plurality of abrasive strips aligned in an overlapping relationship.
In yet another preferred embodiment, the abrasive pad includes a first abrasive member including opposing ends and a pair of side edges extending between the opposing ends, the first abrasive member further including an outwardly facing surface and a plurality of abrasive particles supported on the outwardly facing surface. A second abrasive member includes a loop having upper and lower portions and opposing ends connecting the upper and lower portions, with each of the upper and lower portions having a pair of side edges extending between the opposing ends. The second abrasive member further includes an outwardly facing surface and a plurality of abrasive particles supported on the outwardly facing surface. The second abrasive member is positioned substantially perpendicular to and in partial overlapping relationship with the first abrasive member. A third abrasive member includes a loop having upper and lower portions and opposing ends connecting the upper and lower portions, with each of the upper and lower portions having a pair of side edges extending between the opposing ends. The third abrasive member further includes an outwardly facing surface and a plurality of abrasive particles supported on the outwardly facing surface. The third abrasive member is positioned angularly intermediate the first and second abrasive members and in partial overlapping relationship with at least one of the first and second abrasive members. A fourth abrasive member includes a loop having upper and lower portions and opposing ends connecting the upper and lower portions, with each of the upper and lower portions having a pair of side edges extending between the opposing ends. The fourth abrasive member further includes an outwardly facing surface and a plurality of abrasive particles supported on the outwardly facing surface. The fourth abrasive member is positioned substantially perpendicular to the third abrasive member and angularly intermediate the first and second abrasive members. The fourth abrasive member also is positioned in partial overlapping relationship with at least one of the first and second abrasive members.
The first abrasive member may include a loop having upper and lower portions extending between the opposing ends. The distance between the opposing ends of the first abrasive member may be less than a distance between the opposing ends of the third abrasive member, the distance between the opposing ends of the first abrasive member may be substantially equal to a distance between the opposing ends of the second abrasive member and the distance between the opposing ends of the third abrasive member may be substantially equal to a distance between the opposing ends of the fourth abrasive member. The opposing ends of the third and fourth abrasive members may partially overlap the opposing ends of the first and second abrasive members.
The first abrasive member may be partially received between the upper and lower portions of the second, third and fourth abrasive members, the second abrasive member may be partially received between the upper and lower portions of the third and fourth abrasive members, and the third abrasive member may be partially received between the upper and lower portions of the fourth abrasive member. Each of the abrasive members may be offset angularly from radially adjacent abrasive members by approximately 45xc2x0. Each of the abrasive members may comprise a plurality of abrasive strips aligned in an overlapping relationship.
The above-described abrasive pad may further include a connector supported by the abrasive members and substantially centered intermediate the opposing ends of each of the abrasive members. The connector may comprise an internally threaded rivet extending through each of the abrasive members.
In still another preferred embodiment, the abrasive pad includes a first abrasive strip including a pair of outwardly facing surfaces and a plurality of abrasive particles supported on the pair of outwardly facing surfaces. A second abrasive strip formed into a loop includes a pair of outwardly facing surfaces, a plurality of abrasive particles supported on the pair of outwardly facing surfaces, and a pair of opposing inwardly facing surfaces. The first abrasive strip is positioned at an angle to the second abrasive strip and partially received intermediate the opposing inwardly facing surfaces of the loop of the second abrasive strip. A third abrasive strip formed into a loop includes a pair of outwardly facing surfaces, a plurality of abrasive particles supported on the pair of outwardly facing surfaces, and a pair of opposing inwardly facing surfaces. The loops of the first and second abrasive strips are positioned at an angle to the third abrasive strip and the loop of the first abrasive strip is partially received intermediate the opposing inwardly facing surfaces of the loop of the third abrasive strip. A fourth abrasive strip formed into a loop includes a pair of outwardly facing surfaces, a plurality of abrasive particles supported on the pair of outwardly facing surfaces, and a pair of opposing inwardly facing surfaces. The loop of the third abrasive strip is positioned at an angle to the fourth abrasive strip and is partially received intermediate the opposing inwardly facing surfaces of the loop of the fourth abrasive strip.
The first abrasive strip may be formed into a loop defining the pair of outwardly facing surfaces and a pair of opposing inwardly facing surfaces. Each of the loops formed by the abrasive members may include upper and lower portions and opposing edges connecting the upper and lower portions, the edges of all of the loops being disposed substantially in a single plane. Opposing ends of the loops of the third and fourth abrasive strips may partially overlap the opposing ends of at least one of the loops of the first and second abrasive strips.
Each of the abrasive strips may comprise a plurality of abrasive strips aligned in an overlapping relationship. Each of the loops formed from the abrasive members may be offset angularly from radially adjacent loops by approximately 45xc2x0.
The above-described abrasive pad may further include a connector supported by the abrasive strips. The connector may include an internally threaded rivet.
A preferred method of making an abrasive pad, includes the steps of providing first, second, third and fourth abrasive members each including an outwardly facing surface with a plurality of abrasive particles supported thereon, positioning the first abrasive member substantially perpendicular to the second abrasive member; securing the first abrasive member to the second abrasive member; positioning the third abrasive member angularly intermediate the first and second abrasive members; securing the third abrasive member to the second abrasive member, positioning the fourth abrasive member substantially perpendicular to the third abrasive member and angularly intermediate the first and second abrasive members; and securing the fourth abrasive member to the third abrasive member. The method may further include the steps of folding each of the second, third, and fourth abrasive members to define a loop, a central portion of the first abrasive member to be received within the loop of the second abrasive member, causing a portion of the second abrasive member to be received within the loop of the third abrasive member, and causing a central portion of the third abrasive members to be received within the loop of the fourth abrasive member.
In another preferred embodiment, the method of making the abrasive pad includes the steps of providing first, second, third and fourth strips of abrasive material, each of the strips having first and second surfaces and an abrasive disposed on the second surface; folding the first strip into a first loop wherein the second surface defines a pair of outwardly facing abrasive surfaces, the first surface defines a pair of opposed inwardly facing surfaces, and a pair of end edges connect the pairs of outwardly and inwardly facing surfaces; positioning the second strip in angularly offset relation to the first loop and intermediate the pair of end edges of the first loop, wherein a portion of the first surface of the second strip engages a portion of one of the outwardly facing surfaces of the first loop; folding the second strip into a second loop wherein the second surface defines a pair of outwardly facing abrasive surfaces, the first surface defines a pair of opposed inwardly facing surfaces, a pair of end edges connect the pairs of outwardly and inwardly facing surfaces, and the first loop is partially received intermediate the opposed inwardly facing surfaces of the second loop; positioning the third strip in angularly offset relation to the first and second loops wherein a portion of the first surface of the third strip engages a portion of one of the outwardly facing surfaces of at least one of the first and second loops; folding the third strip into a third loop wherein the second surface of the third strip defines a pair of outwardly facing abrasive surfaces, the first surface defines a pair of opposed inwardly facing surfaces, a pair of end edges connect the pairs of outwardly and inwardly facing surfaces, and the first and second loops are partially received intermediate the opposed inwardly facing surfaces of the third loop; positioning the fourth strip in angularly offset relation to the first and second loops wherein a portion of the first surface of the fourth strip engages a portion of one of the outwardly facing surfaces of the third loop; and folding the fourth strip into a fourth loop wherein the second surface of the fourth strip defines a pair of outwardly facing abrasive surfaces, the first surface defines a pair of opposed inwardly facing surfaces, a pair of end edges connect the pairs of outwardly and inwardly facing surfaces, and the third loop is partially received intermediate the opposed inwardly facing surfaces of the fourth loop.
The method may further include the steps of forming an aperture through the loops intermediate the end edges of loops; inserting a connector through the aperture; and securing the connector to loops. The method also may include the steps of securing the second loop to the first loop after the step of folding the second strip, securing the third loop to the second loop after the step of folding the third strip, and securing the fourth loop to the third loop after the step of folding the fourth loop. The steps of folding the third and fourth strips may include partially covering the end edges of the first and second loops with the end edges of the third and fourth loops.
Additional features and advantages of various preferred embodiments of the invention will be better understood in view of the detailed description provided below.